drivers/usb/usb-common.c

   1 /*
   2  * Provides code common for host and device side USB.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation, version 2.
   7  *
   8  * If either host side (ie. CONFIG_USB=y) or device side USB stack
   9  * (ie. CONFIG_USB_GADGET=y) is compiled in the kernel, this module is
  10  * compiled-in as well.  Otherwise, if either of the two stacks is
  11  * compiled as module, this file is compiled as module as well.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/usb/ch9.h>
  17
  18 const char *usb_speed_string(enum usb_device_speed speed)
  19 {
  20         static const char *const names[] = {
  21                 [USB_SPEED_UNKNOWN] = "UNKNOWN",
  22                 [USB_SPEED_LOW] = "low-speed",
  23                 [USB_SPEED_FULL] = "full-speed",
  24                 [USB_SPEED_HIGH] = "high-speed",
  25                 [USB_SPEED_WIRELESS] = "wireless",
  26                 [USB_SPEED_SUPER] = "super-speed",
  27         };
  28
  29         if (speed < 0 || speed >= ARRAY_SIZE(names))
  30                 speed = USB_SPEED_UNKNOWN;
  31         return names[speed];
  32 }
  33 EXPORT_SYMBOL_GPL(usb_speed_string);
  34
  35 MODULE_LICENSE("GPL");